The present invention pertains generally to pulse-circuit devices and more particularly to high-power switches.
With the advent of pulse lasers and other devices which require high-power electrical-pulse energy for operation such as high-energy lasers and electron-beam accelerators, the requirements for a device capable of producing repetitive high-power pulses of electrical energy have increased greatly. For example, pulsed lasers are now being used in industrial applications for many purposes such as welding and supplying energy to specific chemical reactions. For example, pulsed lasers can be used as a source to clean exhaust gases from combustion by selectively decomposing noxious substances. Simularly, feed stocks for chemical processes can be purified by selective destruction of contaminates. The process of coal gasification can be enhanced using a high-pulse power laser to remove impurities that would adversely effect catalysts used in the gasification process. Moreover, isotope separation processes can be carried out using pulsed lasers to supply feed stocks of elements enriched in a particular isotope. For example, .sup.235 U has been enriched using laser isotope separation processes that employ pulsed lasers to supply a feed stock of uranium for nuclear fission plants.
In order to satisfactorily implement pulsed lasers in industry, long lifetimes and a high degree of reliability are required by these devices. In the past, spark gaps and thyratrons have been used to switch pulse energy with fast-pulse risetimes and high-pulse repetition rates. However, these devices have been unable to provide the necessary pulse repetition rate, pulse risetime, longevity, and reliability necessary for industrial applications.
Considerable effort has been expended to develop a device that is capable of providing high-power dc pulses at high-pulse repetition rates with longevity and reliability. The proceedings of the workshop on repetitive-opening switches (Jan. 28-30, 1981, Durango, Colo.) published Apr. 20, 1981 discloses various opening switches that attempt to provide high-power dc pulses with fast risetimes at high-pulse repetition rates. For example, some of the methods disclosed for achieving repetitive energy transfer include the use of a dense plasma-focus switch, an electron beam-controlled switch, a magnetically-controlled vacuum arc switch, and multiple-fused or explosively actuated switches. None of these devices are capable of providing high-power dc pulses with fast risetimes at high-pulse repetition rates with the necessary reliability and longevity required for industrial applications.